import os
from PIL import Image
#operation_dir="VOCdevkit/VOC/JPEGImages/"
dirname_read="VOCdevkit/VOC/JPEGImages/"  # 最后的斜杠也是路径的一部分，须加
dirname_write="VOCdevkit/VOC/JPEGImages/"

from PIL import Image
import cv2 as cv
import os

def PNG_JPG(PngPath):
    img = cv.imread(PngPath, 0)
    w, h = img.shape[::-1]
    infile = PngPath
    outfile = os.path.splitext(infile)[0] + ".jpg"
    img = Image.open(infile)
    img = img.resize((int(w ), int(h)), Image.ANTIALIAS)
    try:
        if len(img.split()) == 4:
            # prevent IOError: cannot write mode RGBA as BMP
            r, g, b, a = img.split()
            img = Image.merge("RGB", (r, g, b))
            img.convert('RGB').save(outfile, quality=70)
            os.remove(PngPath)
        else:
            img.convert('RGB').save(outfile, quality=70)
            os.remove(PngPath)
        return outfile
    except Exception as e:
        print("PNG转换JPG 错误", e)


if __name__ == '__main__':
    for file in os.listdir(dirname_read):
        if not(os.path.splitext(file)[1]==".jpg"):
            print(file)
            PNG_JPG(os.path.join(dirname_read,file))